mc9s08qd4 Freescale Semiconductor, Inc, mc9s08qd4 Datasheet - Page 170

• Manufacturer Part Number: mc9s08qd4
• Description: Hcs08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Development Support
This section refers to registers and control bits only by their names. A Freescale-provided equate or header
file is used to translate these names into the appropriate absolute addresses.
12.3.1
The BDC has two registers:
These registers are accessed with dedicated serial BDC commands and are not located in the memory
space of the target MCU (so they do not have addresses and cannot be accessed by user programs).
Some of the bits in the BDCSCR have write limitations; otherwise, these registers may be read or written
at any time. For example, the ENBDM control bit may not be written while the MCU is in active
background mode. (This prevents the ambiguous condition of the control bit forbidding active background
mode while the MCU is already in active background mode.) Also, the four status bits (BDMACT, WS,
WSF, and DVF) are read-only status indicators and can never be written by the WRITE_CONTROL serial
BDC command. The clock switch (CLKSW) control bit may be read or written at any time.
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The BDC status and control register (BDCSCR) is an 8-bit register containing control and status
bits for the background debug controller.
The BDC breakpoint match register (BDCBKPT) holds a 16-bit breakpoint match address.
BDC Registers and Control Bits
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor